The impact of the growth of multi-resistant strains of bacteria on human health. Antibacterial resistance has been identified by the World Health Organisation as one of the greatest threats we face globally, now and into the future (World Health Organization. Antimicrobial Resistance: Global report on surveillance 2014). The WHO has identified this major challenge as being one requiring urgent scientific, administrative and governmental action. Since the introduction of antibiotics 80 years ago the quantum of effective drugs has diminished dramatically. Unfortunately this coincided with a diminution of industry-based research and development into new antibiotics (T. Gottlieb, G. R. Nimmo, Med. J. Aust., 2011, 194, 281). US-FDA approval of new antibacterial drugs is at an historic low, and significantly, resistance to new antibiotics can emerge rapidly. In the US, the annual costs associated with treating infectious disease is $120 billion.
In the community, and hence in hospitals, increasing numbers of bacteria; for example, MRSA (methicillin-resistant Staphylococcus aureus), VRE (vancomycin-resistant Enterococcus), multi-resistant S. pneumonia and E. coli, are now resistant to last-line antibiotics such as carbapenems, fluoroquinolines, glycopeptides and third-generation cephalosporins. There is a clear risk of bacterial infections occurring from growth of bacterial colonies and biofilms on surfaces and on medical equipment, such as medical instruments, devices, implants and the like. Antibacterial agents are known. For example, silver nanoparticles have been utilised in a range of applications including healthcare products, home consumer products, clothing and fabrics, food, construction and general disinfectants.
There is a clear need for developing novel agents having antibacterial properties. It would also be desirable to develop antibacterial agents which have properties such that they are suitable for use in preventing spread bacteria on products and surfaces, for example in hospital environments.